Background of the Invention
The present invention relates to a two-wheeled motorcycle, or motorized bicycle, and, more particularly, to apparatus for steering the bicycle. Even more specifically, the invention relates to an apparatus for remotely controlling such a vehicle.
The present invention has particular application with respect to toy motorcycles which are to be directed through turns by remote control, such as by a radio system.
In the past, a wide variety of toy motorcycles have been devised which can be operated in such a manner as to control a movement of the toy. In many cases, the toys were controlled by a tether such as is shown, for example, in U.S. Pat. Nos. 2,699,011; 3,708,913; 3,826,038; and 3,984,105. Since such toys must be attached to a tether to provide suitable control, the ability of the user to observe the toy while it moves is quite limited. While such toys may produce some exercise for the user, they are relatively unsatisfactory from the standpoint of requiring imagination since their movements are limited either by a central pivot for the tether or by the actions of the user who pulls the tether.
Other prior art toys of this general character have allowed remote control via radio or similar means. Such toys are shown, for example, in U.S. Pat. Nos. 3,708,913; 3,751,851; and 3,826,038. In such cases, however, the inventors foresaw the likelihood that their toys would tend to tip over during use. As a result, they usually provided a relatively low center of gravity, as well as auxiliary wheels, imitation foot rests, unusually shaped main wheels, etc., in an attempt to prevent the toy from tipping over. For each such device that the prior art employs, however, the resulting toys appear less and less like the actual machines which were meant to be imitated by the designers.
As a result, children using the toys either do not care for their appearance or else grow tired of them as a result of normal short attention spans, aggravated by the requirement for very little imagination.
Several of the prior art toys also require very complex systems for steering the motorcycles, such as those depicted in U.S. Pat. Nos. 3,546,814 and 3,751,851.
As a result, the prior art toys have been substantially unsuccessful since the people playing with them quickly became bored, the toys themselves were too expensive, or the mechanisms were so complex that they quickly became damaged and/or operated erratically.
In spite of all of the failures of the prior art toys, there still exists a need for a toy which is relatively inexpensive, realistic in appearance and operation, and simple and rugged enough in its construction so that it can be properly operated for a long time. Up until this time, such a toy has not been available.
Summary of the Invention
The present invention relates to a motorcycle which can be remotely steered, such as by radio control, and which obviates the problems of the prior art. In other words, the invention may be embodied in very simple, inexpensive structure which, nevertheless, is sufficiently rugged to withstand the severe punishment normally imposed upon toys. Further, the invention may be employed in any size motorcycle; even one which might be large enough to be a "drone" for experimental purposes.
For the sake of convenience, as utilized herein, a plane which includes the axes of the down tubes, fork, and front wheel axle when the front wheel is aligned with the frame for straight-ahead-travel will be referred to as the "steering plane."
The invention takes into account the fact that, when the pivot axis of the steering crown is in, or behind, the steering plane, the bicycle has a natural tendency to fall over when the center of gravity of the bicycle is shifted to one side. Considering, for example, the case when a bike is upright, it can be presumed that a substantially vertical plane extends longitudinally through the bike from front to rear, with the center of gravity of the bike in that plane. If the center of gravity shifts to one side of the longitudinal plane, the steering mechanism will tend to turn the front wheel toward the opposite side of the plane. For example, if the center of gravity of the bike and its rider, cargo, etc., shifts toward the left of the longitudinal plane, the front wheel will tend to turn toward the right. When this occurs, the bike tends to tip over in the direction toward which the center of gravity has shifted.
While this is also true in the case of full scale motorcycles and bicycles, the tendency for the vehicle to fall is overcome by the rider exerting a force against the tendency of the front wheel to turn away from the direction of movement of the center of gravity.
In toys, of course, this same tendency can be overcome by providing a mechanism which exerts a predetermined force for the same purpose.
In the present invention, on the other hand, the relationship of the structure is such that, when the center of gravity of the bicycle is shifted to one side of the longitudinal plane, the steering mechanism will tend to turn the front wheel in that same direction. This not only helps to prevent the vehicle from falling over, but also positively turns the vehicle in response to the amount of shift of the center of gravity.
This can be accomplished, for example, by providing a steering crown having a pivot axis which is forward of the steering plane. Preferably, the crown pivot axis is parallel to the steering plane. In practice, it has been found to be preferable that the angle at which the steering plane intersects the surface upon which the front wheel rests is between 20.degree. and 25.degree. relative to vertical when the front wheel is aligned with the longitudinal plane. It has been found, for example, that 22.degree. is the optimum angle.
When the present invention is to be employed in a toy or a "drone," it may also employ a weight which may be shifted to one side of the longitudinal plane, described previously, by remote control. In the presently preferred embodiment, the weight may be operatively connected to a servo which may turn a pivot rod in either direction under radio control. With the steering weight connected to the pivot rod, the movement of the center of gravity will be dependent upon the amount that the steering weight is shifted out of the longitudinal plane.
As will now be readily realized, the present invention may be very simply constructed to employ a shiftable steering weight which may be included within a structural combination which causes the front or steering wheel to turn in the same direction, relative to the longitudinal plane, toward which the center of gravity is shifted. Consequently, the structure can be relatively simple while, at the same time, being very rugged, reliable, and inexpensive.
Upon review of the following Detailed Description, taken together with the accompanying drawings, those skilled in the art will realize that the present invention may be employed in a wide variety of embodiments, many of which may not even resemble that described and depicted here. Nevertheless, it should be borne in mind that the description and accompanying drawings are merely illustrative of the principles of the present invention and only set forth the best mode presently known for accomplishing the invention. They are not intended to delimit or restrict the scope of the invention which is defined and limited only by the appended claims.
Brief Description of the Drawings
FIG. 1 comprises a general side elevation of a vehicle employing a preferred embodiment of the present invention;
FIG. 2 comprises an enlarged side view of the vehicle shown in FIG. 1, with various portions eliminated for the sake of clarity;
FIG. 3 comprises a top plan view of the vehicle depicted in FIG. 2;
FIG. 4 comprises a front elevation of the vehicle shown in FIG. 2, as seen along a line IV--IV in FIG. 2;
FIG. 5 comprises a partial elevation view, illustrating the movement of the steering weight, as seen along a line V--V of FIG. 2; and
FIG. 6 comprises an enlarged, partial view, of an alternate embodiment of structure which may be employed to connect the down tube to the fork in the front steering mechanism.
Detailed Description
The presently preferred embodiment of this invention is depicted as vehicle 11 shown generally in FIG. 1, which may comprise a toy or remotely controlled device of any desired size. As illustrated, the vehicle includes a front wheel 13, a rear wheel 15, a frame generally illustrated at 17, a wind fairing 19, and a seat 21. If desired, a rider 23 may be mounted on the seat so that his hands are resting upon a handle bar 25 in the normal manner. Of course, if the vehicle is a toy, it will be realized that the rider 23 may be a doll which is fixed to the seat and handle bars in any desired manner.
Also as illustrated in the drawing, an antenna 27 may be provided for receiving radio signals.
Turning now to FIGS. 2 and 3, it can be seen that the frame 17 is produced so as to extend between a steering crown 41 and the axle of rear wheel 15. A receiver 43 may be mounted on the frame in any suitable manner for cooperation with the antenna 27 for receiving signals in order to produce a useful response in a well known manner. As shown, a motor 45 may be mounted on the frame in such a manner as to drive the wheel 15 by any suitable means, such as a chain belt, or direct drive system 47.
If desired, a battery compartment 51 may be provided so as to house a battery 53 which may be employed to power the motor 45. Similarly, the compartment 51 may house one or more batteries 54 to power the receiver 43.
An intermediate portion of the frame 17 may be enlarged as illustrated in FIG. 3 in the vicinity of the battery compartment 51 in order to provide a suitable mounting space for a servo motor 61 which may be of any well known type. The servo 61 may be connected to a gear train (not shown) within a housing 63 for cooperation with a clutch 65. In this preferred embodiment, an output shaft 67 may extend from the housing 63 and an arm 69 of any desired size and shape may be fixed to the shaft. At the opposite end of the arm, a turning mass or steering weight 71 may be fixed for pivotal movement with the arm when the latter is rotated about the axis of the shaft 67 by actuation of the servo 61. The weight 71 and arm 69 form a steering mass which may be used to exert a torque on the frame 17 to turn the vehicle. The weight is free-swinging, i.e., it is attached to the vehicle only by arm 69, and resembles an inverted pendulum. As will be seen presently, shifting of the weight to one side or the other of the frame will exert a torque which has a tendency to tip the vehicle over toward the side to which the mass is moved. Rather than tip over, however, the specific relationship of the steering mechanism (to be discussed below) will cause the front wheel to turn and steer the bike toward that same side.
The receiver 43 and servo motor 61 may be, for example, of the conventional type of R/C systems long utilized in various models and other devices for remote control thereof. The receiver 43 receives signals from a transmitter 121 (FIG. 1) and causes actuation of the servo motor 61 in response thereto to cause rotation of the shaft 67. Rotation of the shaft 67 rotates the arm 69 and weight 71 about the axis 68 (FIG. 2).
In this embodiment of the invention, it has been found to be desirable to utilize the clutch 65 between the servo 61 and the arm 69 in order to protect the servo. When the receiver 43 is turned off, for example, by a switch (not shown) or removal of the batteries 54, the clutch 65 will slip if the weight 71 is moved to one side or the other due to the application of an external force. The clutch will prevent this movement from being transmitted back through the gear train 63 into the servo. As a result, servo 61 will not be damaged when this occurs. The specific structure of the clutch is not critical to an understanding of this invention, and those skilled in the art will be readily aware that clutches which produce the desired result are readily commercially available.
Referring now to FIG. 3, the motorcycle is shown substantially upright, in a straight-ahead-travel condition. As such, a generally vertical, longitudinal plane, depicted by the phantom line 81, may be considered to pass through the longitudinal center line of the vehicle in such a way that all of the weight or mass of the vehicle, including the motorcycle, the doll 23, etc., is symmetrically located relative to the longitudinal plane. In other words, the center of gravity of the bike is on the longitudinal plane 81. Consequently, the steering weight 71 will shift the center of gravity to one side or the other of plane 81 as it is moved by the arm 69 as shown by the arrows 83 and 84.
In prior art devices of this nature, the general arrangement of the front steering wheel of the bicycle was such that, upon shifting of the center of gravity to one side or the other of the longitudinal plane, the steering wheel would turn in the opposite direction. Thus, if the steering weight, and the center of gravity, shifted to the left side of the plane 81, the steering wheel would turn to the right, and vice versa.
In this embodiment of the present invention, on the other hand, mounting a means, generally designated 82, is provided for mounting the front wheel 13, which is the steering wheel, to the frame 17. The mounting means 82 generally comprises the steering crown 41 which has a top plate 85 and a bottom plate 87. These two plates may be fixedly coupled together by a pivot pin 89 which is always within the longitudinal plane 81. The pivot pin 89 is concentrically enclosed, preferably with a light frictional engagement, within a pivot tube 90 which abuts but is not fixed to either plate 85 or 87. The pivot tube 90 is fixedly coupled to frame 17 by attachment plate 92 as shown at 94. Thus, the steering crown 41 rotates about the axis 96 of pivot pin 89 as pivot pin 89 rotates, in a manner similar to a sleeve bearing, within fixed pivot tube 90.
Referring particularly to FIG. 4, it can be seen that a pair of down tubes 91 may be fixed between the plates 85 and 87 so as to extend below the plates to terminate at rounded ends 93. The axes of the down tubes 91 may be considered to be located in a common plane, that is, the steering plane 113 (FIG. 2), which is parallel to the axis 96 of the pivot pin 89. The steering plane 113, as previously defined, is preferably located behind the pivot axis 96 of the pin 89, as illustrated in FIG. 2. The pivot axis 96, considered in its extension to the surface supporting the motorcycle wheels, intersects the supporting surface at an acute angle, for reasons which will become apparent presently.
Referring again to FIG. 4, it can be seen that a fork 95 may be provided with a pair of rods having upper rounded or hemispherical ends 97 which are preferably located in abutment with the lower ends 93 of the down tubes 91. The lower ends of the down tubes and the upper ends of the fork may be held together by suitable springs 99 having internal diameters which are preferably so sized that the ends of the tubes and fork are tightly gripped by the springs to hold the rounded ends in abutment. Thus, under normal conditions, spring 99 will maintain the axes of the fork shafts and the down tubes in coaxial relationships and in the steering plane.
Front wheel 13 may be rotatably mounted on an axle 111 fixed between the opposite shafts on the fork 95, as illustrated in FIG. 4. Thus, preferably, the axis 112 of the axle 111 is in the same plane as the axes of the down tubes and the fork, i.e, the steering plane 113.
Referring again to FIG. 2, it can be seen that the steering plane 113 may be considered to intersect a generally vertical reference plane 115 at the surface upon which the motorcycle is standing. In practice, it has been found that an angle 117 between the intersecting planes during normal conditions is preferably 20.degree.-25.degree., with the optimum angle being approximately 22.degree..
Due to the relationship of pivot axis 96 and the steering plane 113, as described, when the steering weight or mass 71 is shifted to one side or the other of the longitudinal plane 81, the wheel 13 will tend to turn into the direction toward which the weight has been moved, as shown in phantom in FIG. 3. Thus, front wheel 13 will turn in the direction indicated by arrow 83' when weight 71 moves in the direction indicated by arrow 83; the wheel will turn in the direction indicated by the arrow 84' when the weight 71 moves in the direction indicated by the arrow 84. This turning of the steering wheel 13 is achieved by the relationship of the pivot axis 96 relative to the steering plane 113 and the selection of the angle 117.
It will be realized by those skilled in the art that the fork 95 may be fastened to the down tubes 91 in any suitable manner. On the other hand, the rounded, abutting end-spring combination is relatively simple and inexpensive and allows some shock absorption.
If, while the motorcycle is moving, the front wheel 113 encounters an obstruction or a bump in the surface along which it is traveling, the relationship of the hemispherical ends 93 and 97 of the down tubes 91 and fork 95 will allow some give in the movement of the wheel. The give, however, will be controlled by the tension in the spring 99 which will cause the fork to return to the normal position in a rapid manner.
As a result, a person playing with the toy will be able to drive it into an obstruction, such as furniture, a stair riser, etc., and the vehicle will be rugged enough to withstand such punishment without damage. The user of the toy may generate a radio signal from a transmitter, such as shown at 121 in FIG. 1, causing the signal to be directed to the receiver 43 via the antenna 27. Upon receipt of the signal, the servo 61 will be actuated through the gear train 63 and the clutch 65 so as to move the weight 71 to one side or the other of the longitudinal plane 81. As a result of the shifting of the center of gravity caused by movement of the steering weight 71, the motorcycle will tend to tip in that direction. The relationship of the crown 41 and the steering plane 113 will cause the front wheel 13 to turn in the same direction into which the weight is shifted, thus preventing the bike from tipping over. When the turn has been accomplished, the operator can again actuate the transmitter 121, causing the steering weight 71 to return to the position in which it is centered on the longitudinal axis 81, thus causing the steering wheel 13 to return to the straight-ahead position.
Those skilled in the art will realize that the steering weight may be substantially hidden from view by the body of the "rider" 23 and the fairing 19. This of course, will enhance the appearance of the toy and make it look more realistic. Of course, many such techniques may be employed to modify and enhance structures employing the invention.
Referring again to FIGS. 2 and 3 specifically, it can be seen that a set of lower apertures 101 and a set of upper apertures 103 may be provided near the ends of the battery case 51. Preferably, similar sets of apertures may be provided in both sides of the battery case.
A crash bar 105 may be located in the apertures on one side of the bicycle and a similar crash bar 107 may be positioned in one of the sets of apertures on the other side. The crash bars will help a person using the toy to maintain the toy in an upright position during use. For example, when a person is first learning to remotely control the motorcycle, the crash bars 105 and 107 can be positioned in the apertures 101 on each side of the motorcycle. The crash bars will, in actuality, aid in maintaining the motorcycle in an upright position when it makes a turn or comes to a stop. As the operator acquires more skill, the crash bars can be repositioned into the apertures 103 since there will be fewer times that the motorcycle will tend to fall over during its use. Finally as the operator becomes thoroughly skilled, i.e., he can put the motorcycle through turns without causing it to fall over and can direct it to return to him so that he can pick it up just as it stops, the crash bars can be removed altogether.
Thus, as the skill of the user of the toy improves, his interest will be maintained since the number of times that the toy will fall over and require the operator to reposition it will be minimized. At the same time, the toy will provide a challenge to the operator to both maintain and improve his control skills. The progression of the operator's skills can therefore occur with minimum damage to the toy. At the same time, a beginner will be able to pick up and use the toy without experiencing the frustrations which would arise without the presence of the crash bars. The crash bars will prevent the motorcycle from falling over to one side the or other when it stops, until such time as the operator is so skilled that he can bring the motorcycle back to himself and pick it up by hand just as it comes to a full stop.
Of course, many of the preferred embodiment elements described and depicted here are susceptible to design changes without departure from the spirit of the invention. For example, as shown in FIG. 6, each down tube 91 may be attached to the adjacent end of fork section 95 by means of a spring or flexible rod 99' which may be embedded and/or bonded in apertures of the down tube and fork as shown. Thus, the same type of flexibility can be provided in the steering mechanism with difference structure. Similar design alterations which utilize the invention taught here will now be readily apparent to those skilled in the art.
Having now reviewed this Detailed Description and the drawings of the presently preferred embodiment, those skilled in the art will realize that these merely define a presently preferred embodiment of the invention instead of delimitating it. Rather, it must be kept in mind that the scope of the invention, as set forth in the following claims, is broad enough to encompass a substantial number and wide variety of embodiments, many of which may not even resemble that depicted and described here. Nevertheless, such additional embodiments will employ the spirit and scope of the invention which is established only by the following claims.